Differential mechanism.



D. E. ROSS.

DIFFERENTIAL MECHANISM.

APPLICATION FILED APR.12,1912.

'Patented Mar. 14, 1916.

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APPLICATION FILED APR.12. i912.

Patented Mar. 14, 1916.

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DAVID E. BOSS, OF LA FAYETTE, INDIANA, ASSIGNOB T0 ROSS GEAR AND '.lOOL COMPANY, OF LA FAYETTE, INDIANA, A CORPORATION OF INDIANA.

DIFFERENTIAL MECHANISM.

To all whom t may concern.' g

Be it known that I, DAVID E. Ross, of La Fayette, in the county of Tippecanoe and State of Indiana, have invented certain new and useful Improvements in Differential Mechanism; 'and I hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, which form part of this specification.

This invention is a novel improvement in diiferential mechanism and its object is provide a differential mechanism wherein one driven member cannot or will not race if less resistance should be ofered thereto than to the other member; for example, if the mechanism is used to drive the rear wheels of an automobile, one driven wheel cannot race if it finds a soft place; and thus all the motive power can be utilized for effective tractive purposes, and not be wasted in driving any part idly.

Another object is to provide a differential mechanism containing the invention which can be substituted for or used in place of certain types of dierential mechanism now in use with the advantage of economizing 'motive power and preventing racing as above noted.f--

I will explain the invention in detail as embodied in.;l the diierential mechanism illustrated' inA the accompanying drawings in which-.-

Figure 1 is a central longitudinal sectional view through a differential mechanisri` embodying the invention. Fig. 2 is a vertical transverse section on the line 2-2, Fig. 1. Fig. 3 is a side View of the roller cages. Fig. 4 is a longitudinal sectional elevation of such a mechanism provided with cage controlling springs. Fig. 5 is a transverseA section on line 5 5, Fig. 4. Fig. 6 isa detail view of the cage-controlling castings shown in Figs.' 4 and 5. Fig. -7 is a side view of one of such castings. Fig. 8 is a detail perspective view illustrating the operation of the cage-controlling devices.

Referring to Figs. 1 and 2 of the drawings, 1 designates a diierential housing or casing which is in the form ofa cylinder closed at its ends by heads 3 which'are fitted to the ends of the housing and secured rigidly thereto by means of longitudinal bolts 3a. `These heads are-provided with axially alined hubs or bearings 3b for the inner ends Specification of Letters Patent.

Patented Mar. 14, 1916.

Application led April 12, 1912. Serial No. 690,360.

of the shaft or axle` sections A, A', hereinafter referred to.

The housing 1 is adapted to be rotated axially by any suitable means. As shown a bevel gear l*l is secured thereto by'means of bolts 1; and this gear l may be driven by means of a pinion 1d connected to the engine shaft, (not shown) or any other suitable driver. The particular means for rotating the housing 1 forms no part of the present invention.

Within the-casing 1 are a pair of adjacent disks 7, 7a which are respectively keyed or otherwise fitted to the ends of the shaft sections A, A', vso that they cannot rotate relatively thereto. Each disk, 7, 7, is provided with a plurality of pockets 7 c in its periphery; and normally resting in the pockets of the disk 7 are rollers 8, and in the pockets of disk 7?* are rollers 8. These rollers lie be tween the disks 7, 7 a and the interior wall of the housing and project from the pocket 7c into corresponding pocket 1e in the inner periphery of the housing `1. The pockets 1 in the housing are longer circumferentially than the pockets 7 in the disks, and consequently as the housing turnseach roller 8, 8a will eventually be caught between the following end of a pocket 1e in the casing and the leading end of a pocketv 7c in its disk` as indicated in Fig. 2; and the rollers thus form a clutch or lock between the casing and the disks, and transmit motion from the housing 1 to the disks in the direction in which the housing rotates.

The pockets 1 in the housing preferably have contracted extensions at their ends, as indicated at 1f, which fit the side of the rollers and afford broad bearing surfaces for the rollers 8, 8n when the housing is locked If either disk Y to the disks by the rollers. moves to an intermediate position, so that the pocket 7 therein registers about centrally with the pockets 1 of the housing, then the roller 8, (or 8a) in the disk would project into pockets 1e as indicated in dotted lines in Fig. 2 and would not transmit motion from the housing to the disks, or lvice versa.

10 preventexcessive rotary movement of one disk relative to.the other each set *of rollers is kept properly spaced apart by a cage. As shown the rollers 8 are spaced apart by a cage 6 which may consist of an annular band slightly larger in diameter than the disk 7 and fitted loosely thereover and provided, with openings 6b to accommodate the rollers 8, and which while permitting each roller to freely rotate, keeps them pioperly spaced apart. The openings 6b in cage 6 correspond in location to the .pockets 7c in the disk 7. The rollers 8a are similarly spaced apart by being placed in openings 6c in a cage 6a loosely fitted over the disk 7a.

The cages 6. and 6a, see Fig. 3, are provided at their inner ends with lugs 6d and recesses 6; the lugs 6d of one cage project into the recesses 6e of the opposed cage. The recesses are of greater circumferential eX- tent than the lugs so as to permit one cage to move circumferentially for a limited extent relatively to the other; but in the normal position of the parts, lugs 6d lie in the center of the recesses 6e. The action of these lugs is hereinafter explained.

Under normal conditions with the parts constructed and arranged as shown in Figs. 1 and 2; when the housing 1 is driven it causes disks 7, 7 to rotate by reason of the rollers 8, 8 in the pockets of the disks engaging with' the opposed shoulders of the pockets 1e of the housing l. Assuming for instance that the device is used on an automobile and that the aXlesA, A are connected to the respective driving wheels at opposite sides of the vehicle; when the vehicle turns, one drive wheel will necessarily have to travel faster than the other, and in such case assuming that the disk 7 is connected with the faster wheeL, it would advance or rotate ahead of the disk 7a until the following 'side of the pocket 7c engaged the rollers 8 and forced these rollers forward toward the center of the pockets 1"' in the housing, at which time the lugs 6d on the cage 6 would engage the forward end of the recesses 6@ in the cage 6a. The cage 6a however will be prevented from rotating because the rollers 8a which are fitted in the pockets therein are then driving the whole load and locked between the forward ends of the pocket 7c in disk 7a and the following of the pockets 1e in the housing. Under these conditions therefore rollers 8 will assume a position indicated in dotted lines in Fig. 2, out of Contact with the ends of pockets l of the housing, and rotate idly; and the disk 7 could then rotatepast said rollers 8 which cannot advance any farther toward the lleading end of the pockets le in the housing because cage 6 is prevented from moving forward by the interlocking lugs and recesses on the cages 6, 6a; the disk 7 however is free to advance any fraction of a revolution or number of revolutions. But when the vehicle has turned a curve and is again going directly forward, and the wheels turn at a uniform speed the rollers 8 will drop into the pockets 7 in disks 7 and be again engaged by the following edges of the v disk 7, then the rollers in 6a Fig. 8; and between and within pockets 1 in the housing 1, asindicated in full lines, and transmit motion from the housing 1 to the disk 7 and connected wheels. With this compensating mechanism the wheel on the solid ground is always doing the driving and it is impossible for the wheel in slippery places to race and absorb the -power of the driving mechanism. If the wheel attached to axle A should be the faster wheel in turning the corner then the rollers 8 disk 7 a and cage 6a would operate in the same manner as the rollers 8, disks 7 and cage 6 above described.

It can readily be seen that the parts 6 and 6a (which are duplicates of each other) can have but a limited amount of rotation with respect to each other, as the lugs of one are arranged to engage the recesses of the other.

Supposing the rollers in 6 were driving andl the rollers in 6a should force 6 to rotate ahead' of 6; immediately the lug on 6a will rollers being engaged with the housing and cannot advance far enough to come in contact with the forward wall of pockets 1e and cause any interlocking action in that direction. s When the rollers pass out into the pockets 1" there is no tendency on the part of such rollers to cause any additional rotation of cage 6a with respect to 6. If, however, the vehicle should race on ahead of the motive power, then both cages will permit their rollers to go ahead and lock in the forward position. This is equally true Where the driving mechanism is reversed.

If the car is to be run at such a speed that the centrifugal force might be greater than the weight of the rollers and tending to hold them out in the pockets 1-, then it may be advisable to use a spring-controlling device to force the cages 6 and 6 into alinement.

One spring means for controlling the relative position of the cages 6, 6 is shown in Figs. 4 and 5. In this construction the cages 6, 6a are provided on their adjacent edges with opposite projecting lips 6, see the cages and intermediate the disks 7, 7a are placed two castings (Fig. 7) each comprising an annular ring 11- having diametrically opposite radially projecting arms llfgwhichcastings are duplicates so that they can befitted together as indicated in Fig. 6 and when so fitted together arms 11 of one casting will come opposite similar arms of the-opposite casting and form a kind of X-lever. The

annular parts 11 are rotatably' mountedl supported in annular recesses in the inner faces of said disks 7, 7a (see Fig. 4). Theopposed arms 11a of the castings 11 engage the opposite sides of the lugs Gf of the cages 6, 6a (see Fig. 8) and between the arms 11a of one casting 11 and the diametrically opposite arms 11a of the other casting 11 are forward until it engages the leadingj'edge 6gr of the recess in the cage 6, which will prevent any further rotation of the cage 6. It will be seen by reference to Fig. 5 that such movement of one cage will put springs 9 under compression and therefore said springs will return the displaced cage to normal position as soon as the disturbing pressure on either cage is released, and this will bring the openings in cages 6, 6?* into alinement and both sets of rollers 8, 8a will be brought into effective operative position.

In the construction shown in Fig. 4 the housing is shown as divided centrally into two parts, secured together by bolts; but with the exception of having the disks 7, 7 a separated suiiiciently to enable the cage controlling devices to be inserted therebetween, the construction is similar in purpose, effect and operation vto that already described.

In case one wheel should run faster than the other, as in turning a corner, the related disk and its rollers are forced forward by the differential wheel making the gain but the rollers, being in a cage, can be advanced only as faras such cage can advance; and such cage is stopped by the other cage which is surrounding the other driving rollers (see Figs. 3'and 8). The advanced rollers are then forced into the outer pockets 1e as indicated in dotted lines in Fig. 2. For low speed differential mechanism wherey the centrifugal force would not be abnormal, no

spring returning mechanism would beA necessary, but for high speed differential mechanism the rollers would have a tendency to stay in the outer pockets, so it-becomes necessary to provide some spring mechanism for returning the displaced rollers to normal position.

Running under normal conditions the rollers 8, 8 will-be in alinement. When a corner is reached, the inner slower wheel will be driven; while the outer wheel, traversing the most territory, will idly gain the required amount; but will immediately be driven as soon as the corner is turned, or the disturbing factor removed.

What I claim is: Y

l. In a differential mechanism, the combination of a housing, a pair of disks mounted axially within said housing, and clutch devices interposed between the disks and housing and adapted to lock them together, a means surrounding each disk and keeping the clutch devices thereof in proper' relative position. and devices whereby one of said means llimits the relative rotary displacement of the other set. f

2. In a differential mechanism, the com.v

bination of a housing, a pair of disks mounted axially within said housing, and clutch rollers interposed between the disks and lhousing and adapted to lock them together,

a cage surrounding each disk and keeping the rollers thereof in proper relative position, and means whereby one cage limits 'the relative rotary displacement of the other.

3. In a differential mechanism, the combination of a housing provided with a series of pockets in its interior; a pair of disks mounted axially of and within said housing and provided with pockets in their periphery; clutch devices in the pockets of the disks adapted to project into the pockets of the housing and to lock the disks to the housing; ameans operating with each disk for keeping the clutch devices thereof properly spaced apart; one means limiting the relative displacement of the other means.

4. In a differential mechanism, the combination of a housing, a pair of disks mounted` axially within said housing, and clutch devices interposed between the disks and housing and adapted to lock them together,

a 'cage surrounding each disk andkeeping'l the clutch devices thereof in proper relative position, and spring-controlled devices for returning a displaced cage to normal position.

5. In a differential mechanism, the combination of a housing; a pair of disks mounted axially within said housing; clutch rollers interposed between the disks and housing and adapted to lock them together means for keeping the rollers of each disk in proper relative position, means whereby one set of'rollers limits the relative rotary displacement of the other set; and springs for returning a displaced set of rollers to normal position.

6. In a differential mechanism, the combination of a housing provided with a series mounted axially of and .within said housing and provided with pockets in their periphy ery, rollers in the pockets of the disks and adapted to project into the pockets of the housing and to lock the disks to the housing;

cages for keeping the rollers in each disk properly spaced apart; and means whereby one cage limits the displacement of the other A disks adapted to project into the pockets of the housing, a slotted cage surrounding each disk and spacing the clutch devices apart, and means for limiting the relative rotary displacement of the cages.

8. In a differential mechanism, the combination of a housing having an annular series of pockets in its inner periphery, means for driving the housing; a pair of axially alined disks mounted axially Within the housing and provided with peripheral pockets; rollers in the pockets of the disks and housing adapted to lock the disks to the housing; an annular slotted cage surrounding each disk and provided with slots for the accommodation of the related rollers; and means for limiting the relative rotary displacement of the cages.

9. In a differential mechanism, the com' bination of a housing having interior pockets; a pair of disks axially mounted Within said housing and provided with pockets; clutch devices in the pockets of the disks adapted to project into the pockets of the housing, a slotted cage surrounding each disk and spacing the clutch devices apart; and spring-controlled means for normally holding the cages with the clutch devices in alinement and for returning the displaced cage to normal position.

10. In a differential mechanism, the combination of a housing having an annular series of pockets in its inner periphery; means for driving the housing; 'a pair of axially alined disks mounted axially within the housing and provided with peripheral pockets; rollers placed in the pockets of the disks and housing adapted to lock the disks to the housing; and an annular slotted cage surrounding each disk and provided with slots for the accommodation of the related rollers; with spring-controlled devices for normally holding the cages in alinement, and for returning the displaced cage into alinement.

1l. In a diierential mechanism, the combination of a housing, a pair of disks mounted axially within said housing, and clutch devices interposed between the disks and housing andl adaptedV to lock them together, a cage surrounding each disk and keeping the clutch devices thereof in proper relative position, and spring-controlled devices for returning a displaced cage to normal position; said devices comprising a pair of pivoted X-levers arranged intermediate the disks the opposite levers engaging opposite sides of adjacent lugs on the cages, and springs interposed between the opposite 5 rounding each disk and provided With slots for the accommodation of the related rollers,

with devices for normally-holding the cages in alinement, andA for returning the displaced cage into alinement; said devices comprising a pair of pivoted X-levers arranged inter-,p

mediate the disks the opposite levers engaging opposite sides of adjacent lugs on the cages, and springs interposed between the opposite ends of opposite levers to close the X-members.. p

13. Ina dil'erential mechanism, the combination of'a housing; a pair of members mounted axially within said housing; clutch rollers interposed between the members and housing and adapted to lock them together; and means whereby one set of rollers limits the relative rotary displacement of the other set; and means for returning a displaced set of rollers to normal position.

In testimony that I claim the foregoing as my own, I aiix my signature in presence of two witnesses.

DAVID E. ROSS.

vWitnesses:

EDWARD A. Ross, WM Ross. 

